Ultrasonic velocity measurements for characterizing the annealing behaviour of cold worked austenitic stainless steel

摘要: Precise measurements of shear wave velocities have been made in 20% cold worked and annealed samples alloy D9 (Ti-modified austenitic stainless steel) to characterize the microstructural changes during annealing. The variation velocity with annealing time exhibited a three stage behaviour. In first stage, slight increase recovery regime has observed. This is followed by significant recrystallization (second stage) reaching saturation on completion (third stage). Microstructural observations using optical metallography confirmed these stages. maximum observed only when polarization or propagation direction alingned working direction. Variation process, general, just opposite that longitudinal velocity. A number were changing directions waves respect Based measurements, suitable ratio parameter suggested for determining degree D9.